1. Field of the Invention
The present invention relates to a high density multi-layer optical disc on which multiple layers are formed, a method for recording data thereon on a layer-by-layer basis, and a method for managing spare areas thereof.
2. Description of the Related Art
As standardization of a high-density rewritable optical disc, e.g.; a Blu-ray disc rewritable (BD-RE), capable of storing high-quality video and audio rapidly progresses, it is expected that related products will be developed, commercialized and supplied.
A conventional BD-RE single layer 100 is shown in FIG. 1. As shown in FIG. 1, there is a distance of approximately 0.1 mm between a recording layer and the surface of a transparent film being arranged between the recording layer and an objective lens (OL) 11 of an optical pick-up.
When an optical disc apparatus for reading and reproducing data recorded on the recording layer of the BD-RE single layer 100 or recording data thereon determines that a defect is detected on the layer 100 while performing a data recording operation, the optical disc apparatus records the data in an inner spare area (ISA) or outer spare area (OSA) separately assigned to a data area as shown in FIG. 2, in place of a data area.
Further, the optical disc apparatus generates a defect list (DFL) entry needed for identifying a cluster associated with a recording unit block {RUB} recorded in the spare area in place of a data area, and performs a recording and management operation for the generated DFL entry.
As shown in FIG. 2, management information associated with the spare areas is contained and recorded in a field of rewritable disc definition structure (DDS) information of a lead-in area. The DDS information includes information items associated with the first physical sector number (PSN) of the DFL (P_DFL), a location of a logical sector number (LSN) 0 of in user data area, the last LSN of the user data area, a size of the ISA (ISA_size), a size of the OSA (OSA_Size), spare area full flags indicating whether the respective spare areas are full, the last verified address (LVA) pointer, etc.
The spare area full flags are recorded by one byte consisting of a 1-bit ISA full flag, a 1-bit OSA full flag and 6-bit reserved information assigned to a reserved area.
As described above, when the defect is detected in the data area while the optical disc apparatus records data in the data area, the optical disc apparatus searches for the spare area full flags contained and recorded in the DDS information field, selects the ISA or OSA in which the data can be recorded, and performs a sequence of data recording operations for recording the data in the selected spare area.
A high-density dual-layer optical disc, i.e., a BD-RE dual layer, capable of recording twice as much video and audio data as the BD-RE single layer, has been developed. As shown in FIG. 3, there is a distance d2 between the first recording layer (Layer 0) and the second recording layer (Layer 1) formed in the BD-RE dual layer 200. The first and second recording layers are formed at a location, within the BD-RE dual layer 200, having a bias toward the OL 11 of the optical pick-up.
The first and second recording layers of the BD-RE dual layer 200 are linked to each other so that the large-capacity data can be recorded. The ISA and OSA can be separately assigned to each of the data areas associated with the first and second recording layers. However, there is not yet provided a method for efficiently employing the first and second recording layers of the BD-RE dual layer 200 on a layer-by-layer basis. Moreover, there is not yet provided a method for efficiently employing and managing a plurality of spare areas separately assigned to each recording layer.